Mirum Pharmaceuticals, Inc. (MIRM) Earnings Call Transcript & Summary

All right. Hello, everyone, and thanks for joining us at the Morgan Stanley Global Healthcare Conference. I'm Mike Ulz, one of the biotech analysts here. It's my pleasure to introduce Chris Peetz, CEO from Mirum Pharmaceuticals. Just as a quick reminder, the format for today is a fireside chat, but if anyone in the audience has a question, you can raise your hand and we'll try and address it in our discussion here. But before we get started, I just need to read a quick disclosure. For important disclosures, please see the Morgan Stanley research disclosure website at www.morganstanley.com/researchdisclosures. And if you have any questions, please reach out to your Morgan Stanley sales representative. And with that, Chris, -- thanks for sharing your time with us today, and maybe I'll just hand it over to you to make some introductory comments.

Yes. Thanks for hosting. Great to be here. And I'll make a quick disclaimer on my end as well. be making forward-looking statements, so I refer you to the SEC filings for Mirum for a more complete risk factor disclosure. And a bit about Mirum, we are a company that's established just under 8 years ago and focused on pulling together high-impact medicines for rare disease that are often overlooked, missed by some of the bigger companies but really compelling opportunities, not only from patient impact, but also as a business model and pulling these together in an efficient way. This year, we're on track for $680 million to $700 million of revenue across 3 approved medicines really had a kind of emerging growth trend in one of our indications, in particular, with that I'm sure we'll spend some time talking about. And a pipeline that is very busy right now. So later this quarter, later this month, actually, expecting to announce top line data of the AZURE 1 Phase III study of brilovetug in hepatitis delta. We have a PDUFA date from one of our newly added programs in FOP more readouts, two more Phase IIIs reading out next quarter and another study in PBC, first quarter next year, all this on the back of entering into a regulatory conversation for PSC for volixibat as well. So it's a busy stretch for Mirum. And kind of on the other side of this, see a real inflection on business performance from all of these data readouts and launches that we expect in the near term, exciting time across the board.

Yes. Great. Thanks for that introduction. Yes, lots to get through here. So maybe we just start with the commercial business and Live Marley and you touched on this in your prepared remarks, but you're seeing some nice sort of growth in PFIC. So maybe talk about what you're seeing there and how you think about that going forward?

LIVMARLI is approved in 2 different indications, cholestatic pruritus due to allogelsyndrome and choosieritis due to PFIC. And first approval in Alagille syndrome continues to be a growth driver. So we, across the board, continue to see new patient starts the response profile for most patients is quite meaningful and see strong compliance and persistence as well. So that plays well for the brands over time, both this is U.S. as well as international performance. The PFIC indication was added subsequent to the Alagille syndrome launch -- and it's been an interesting story over time. Initially, we saw us as a pediatric opportunity. That's what our field team is primarily targeting and finding the pediatric profile of the PFIC patient -- as we've been in market with LIVMARLI in Puratos dudopetic, we've found that there is also a substantial underdiagnosed population in adults that actually have PFIC and have, to date, been labeled as idiopathic cholestasis. So really just an incomplete diagnosis in many of these adult cholestatic patients with pruritus. And that's something that we've seen start to contribute to the top line over the past year. Very durable trend in everything we're seeing. In fact, we're now in the process of expanding the field commercial team to help support some of that patient finding and diagnosis help build awareness of genetic testing and availability of it for adult patients. We estimate there's probably about 2,000 adult PFIC patients in the sale market that are out there in the U.S. So that's kind of one of the near-term drivers for the continued growth on the commercial business.

Yes. As we look next year and beyond, you also have a Phase III EXPAND study ongoing that could even further expand the opportunity there. So maybe just talk a little bit about that, maybe give a little bit of background how you ended up sort of targeting that indication and what to expect when we see data I think in the fourth quarter.

Yes. LIVMARLI as a whole, we see it as a $1 billion-plus brand opportunity driven by all these different components, expand being a substantial contributor to it as well. It is a basket study. So it's a collection of ultra-rare causes of cholestatic pruritus that by definition in our discussion with the FDA are too small to run a stand-alone study in. So good number of them in the study are biliary atresia. That's probably the only one that's a little bit more common of the mix and then very small numbers of other genetic and nongenetic causes of cholestasis that end up with a pure its presentation. Study looks at both pediatric and adult patients, the readout, the primary endpoint that we're expecting next quarter is in a pediatric cohort. That's what the study was primarily powered and designed around. So expect to see that as the top line next quarter, the pediatric patients with an identified subset looking at biliary atresia as well as a secondary because it is about half of the patient population. There's probably 500 pediatric patients in the U.S. that make up the addressable market that we've kind of identified in size. It's an early estimate. It's hard to tell how big of an indication this could be in adult settings as well. There are some adult patients out there, certainly, we just don't know quite how many. So it's a nice add-on to what we're already seeing in Algea syndrome and PFIC.

Can you talk about what drives your confidence in being successful there? Any prior data you can put to.

Yes. There's -- really, the justus of the study design came from physician interests in compassionate use case studies. So we do have not in a clinical trial format, but we do have anecdotal case study evidence seeing response in a number of these types of settings. Bill are atresia, in particular, we presented some of the case studies of a series of biliary tesa patients with cholestatic pruritus being treated. And it's what you'd expect for an iBAT treatment in a patient with cholestasis, elevated bile acids and itch, you can expect to see a nice response in the clinical data that comes out from those studies.

Great. And if we just sort of stick with the commercial portfolio and specifically the bile acid portfolio, you added that a couple of years ago, and it seems to be performing well. So maybe just talk a little bit about that, what's driving that and the outlook there?

The bile acids sitex and koldam have grown nicely with a dedicated team behind it. One of the things to note when we brought those products in, realization we had is that the prescriber universe is not entirely hepatology in GI -- many of these patients, in particular for Setexly and for some of the kbom indications are in medical genetics or neurology, and it's more of a patient-finding diagnosis effort that doesn't exclusively happen in hepatology. So we built a separate team that focuses on those other settings and the patient finding -- and they've done a fantastic job over time with these products. And it's about having a dedicated effort that is -- it's a different strategy than what the liver team is doing. So it makes sense to have a different team staffed against it. And actually, it fits really well with one of the things to come on FOP. That's the team that's going to be launching zolargesirtib in FOP. And it's a really similar effort, overlapping call points in terms of the institutions that these people are visiting and in contact with a similar effort in terms of following data on diagnosis and leveraging some of the referral patterns that happen for these ultra-rare conditions like FOP, like CTX.

Yes. Maybe talk a little bit more about FOP and kind of what attracted you to that asset and kind of what drove that decision?

Somewhat from kind of what I was just talking about with our expansion into medical genetics and kind of thinking of rare disease as a therapeutic area. We've been looking for other programs that could fit with that kind of team and call points to put more in the hands of the team that's been executing so well. As we've started looking into FOP and the programs being run there, the biology and the data are striking. So this program that Incyte did all the work on the Phase II study that supported the NDA submission, really compelling data that's come out of that showing that you can really versus placebo have a striking difference in the volume of ossification that build up over time for these patients. We see this as groundbreaking data for FOP patients to be able to halt that formation of new ossification dramatically change the course compared to placebo in those data sets. So both that clinical data and how clear it is as well as the fit with our team and business model comes together in a great story. And with the conversation with insight, it's a story of focus between 2 companies, right? This was something that didn't fit with their business model is clearly aligned with what we're trying to do. So it was a natural transition that we set up.

Yes. Makes sense. With the PDUFA date coming up here, can you just talk about launch preparations? Can you hit the ground running sounds like you probably can, but maybe just talk a little bit about that.

Yes. Even for launch preparations, field team, it's the same team that's already out there for the bile acid medicines. So in terms of the staffing, largely that's all in place. And so we're ready for the PDUFA date and decision in a couple of weeks here. Looking to -- that's the point that triggers a transition of sponsorship from Insight. So a couple of steps there to get this launched in Q4. .

Okay. Great. as we've been sort of on the topic of BD, you've obviously been pretty active over the past few years. So maybe just talk more broadly about your BD strategy, your thoughts currently? Are you looking to add more programs? Or do you have enough catalysts over the next 6 months?

We're a little busy for the next 6 months, when it takes time for these deals to come together -- which I think is -- I mean that's behind the overall strategy for how we got to where we are today. And the vision for the path forward is to always be active -- to find the opportunity that is compelling both from the biology data and patient impact, but then also that fits with the Mirum business model that you can have an intersection where the deal economics work for both sides. It takes time and being a little bit opportunistic. So we never rest on the BD front. We're always active looking at things -- the range of things that could be of interest remains the same. Phase II opportunities through to early commercial are all of interest and could fit well. But granted the next 6 months are a little packed -- so adding a Phase II sounds like a pretty good idea to me instead of another launch next year.

Yes. Understood. And I guess what areas of focus? Is it like rare genetic liver? Could you go outside that at all? Or is that -- does it make sense for you or.

Yes. We look outside of liver and outside of the broader current therapeutic areas where we're active because we see rare disease as therapeutic area as the expertise that we bring. So the ability to commercialize medicines where they are maybe harder to diagnose, harder to get to a point of care where there is maybe a first product in class or in the indication and kind of setting and changing the standard of care. These are the types of opportunities that our team has shown that they can execute on. And so it's not so much tied to the specialists but more the model around a rare disease product launch. And we're seeing, as we saw with the bile acid products how we're approaching the zolurgasertib launch, you can leverage this into new therapeutic areas pretty easily. So adding on the endocrine call point in some of these tertiary centers for the -- what we call the GM team is pretty straightforward, actually.

Maybe we can keep it rolling moving to volixibat, and maybe just start with PSC and just maybe talk a little bit about the market opportunity there and the unmet need and how you see it.

So backdrop of PSC as an indication, this is autoimmune-driven cholestatic condition presents most commonly in adults, but there is a pediatric onset form of it as well, and hallmark of it being the fibrotic strictures forming around the bile duct leading to progressive liver complications. It's also associated with frequent episodes of cholangitis, highly variable liver labs and just really a very difficult setting to treat clinically. And it's been very tough for drug developers historically. So we've seen a number of programs early on exploring different endpoints using histology, using different biomarkers. None of those have really panned out. When we approached it with volixibat -- we're coming at it with -- from a different angle. So leveraging some of what we learned on the pediatric side using the symptomatic burden as the endpoint for our registration program. And clear that pruritus is a substantial clinical burden for these patients that aligned well to be an endpoint in PSC similar to how we've used that in syndrome and PFIC and PBC. So a good precedent for how it's used in other settings. And with the Vistas program in PSC for volixibat, which I'm sure we'll talk about kind of diving into it here. I had that conversation with FDA, good clear written correspondence discussing the study design, the registrational intent pruritus as a substantial patient need end point and indication and had good alignment on the study design and announced earlier this year, really strong top line data. So clear had presented at EASL this year, a really compelling impact on pruritus in the VISTA study for volixibat in PSC.

You also shared that positive data with the FDA and the FDA sort of requested Phase III. So maybe just walk us through what happened there? And what are your thoughts on that going forward from here?